1. Field of the Invention
This invention relates to fluid dispensing and more particularly to a system for mixing a hot liquid with a cold liquid for dispensing the mixed liquids at a controlled temperature.
2. Description of the Prior Art
Various types of devices have been used for controlling the temperature of a liquid dispensed from a system. In addition, various types of liquid temperature controlling devices have found use in industrial, commercial residential and medical applications. One particular application for liquid temperature controlling devices is in the dispensing of water in bathtubs, sinks, showers and the like in homes, nursing homes, and medical complexes.
Historically, many types of baths and bathtubs have been manufactured which are well known to the prior art. The Romans were well advanced in engineering ingenuity as to the provision of various types of water systems including baths and waste water disposal devices. More recently, attention has turned to the manufacture of a bathtub that will not only enhance the ease with which an operator may take a bath or shower, but more particularly a need has existed in the art for controlling the temperature and flow functions of water within the bath, shower or a sink. In the past, it has been customary for a person desiring a bath to manually close the drain plug and manually open the hot and cold water faucets to the required setting to fill the bath with the requisite level of water at the desired temperature. When the water level had reached the required height, the faucets were closed and the bath was ready for use.
Although the foregoing system which should be well known to those skilled in the art have satisfied the needs for decades, certain problems have been experienced in carrying out the various operations of the prior art system as outlined hereinbefore. First, the process of bending over a bathtub to close the drain presents a serious problem for many elderly or infirm persons. Second, when a bath is to be filled and the hot water faucet is opened before the cold one, scalding can take place unless an incorrect setting is made to the hot and cold water faucets. Third, a period of time is normally required for the hot water to run at the faucet before the running hot water obtains the proper hot water temperature. While the hot water is running and being discharged to the drain, the water is being wasted in addition to wasting the energy required to heat the hot water which is at an elevated temperature but below the temperature desired by the operator. Fourth, if the flow of water from the open faucet is relatively slow, there exists a temptation to become involved with another task while the bath is running which may results in the waste of hot water due to overfilling or possibly the overflow of the bathtub if the faucets are not closed when the proper water level is reached in the bathtub. Fifth, there is no provision in a conventional bathtub to maintain the water in the bathtub at the desired temperature and at the desired water level.
Some in the prior art have developed various devices in an attempt to solve the problems in the prior art as heretofore described. Although these prior art devices have solved some of the specific needs of the liquid dispensing art, none of these prior art devices have contributed a total solution to the liquid dispensing art and specifically to water dispensing systems.
U.S. Pat. No. 2,001,329 to Wayer discloses a mixing valve for a faucet having a plurality of ports in a cylindrical valve casing in combination with a longitudinally movable piston for mixing a hot and a cold liquid.
U.S. Pat. No. 2,877,467 to Cloud illustrates a control system for controlling various functions of a bathroom which enables a bather to fill a bathtub to a required level with water at a desired temperature and to drain the tub after use by the bather. Unfortunately, this control system was expensive and overly complex and never obtained wide acceptance in the art.
U.S. Pat. No. 2,991,481 to Booke discloses an electronic control circuit for controlling the mixing of hot and cold water from a supply prior to flowing into a bathtub. Although this invention describes an overflow shut-off device for stopping the flow of water into the bathtub when the water level reaches an overflow condition, no disclosure is made of a selective control of the water level. Furthermore, no disclosure is made of a means for maintaining a preselected temperature of the water within the bathtub.
U.S. Pat. No. 2,991,482 to Brass, describes a side entry bathtub for aiding the entry of elderly or infirmed persons into a bathtub. The mechanism of this device is unfortunately overly complex and costly and subject to failure in a typical bathroom environment. In addition, the mechanism is not interrelated with a water dispensing system.
U.S. Pat. No. 2,969,923 to Fremion discloses a water mixing arrangement for a shower and a bath having a housing with a first and a second input port in combination with a hollow slide value to control the proportion of hot water and cold water entering the first and second input ports upon longitudinal movement of the slide valve.
U.S. Pat. No. 3,298,395 to Lewis shows a sequence valve for mixing a hot liquid and a cold liquid with the valve being powered by a hydraulic force operating on a flexible diaphram.
U.S. Pat. No. 3,561,481 to Taplin similarly illustrates a mixing valve powered by a hydraulic force for longitudinally moving a piston to control the flow rate of a first and a second liquid entering into the valve for mixing the first and the second liquids to discharge from a common outlet.
U.S. Pat. No. 3,771,562 to Curran discloses a three-way industrial valve suitable for both flow conveyance and flow divergence and adapted for use with pneumatic actuators.
U.S. Pat. No. 4,042,984 to Butler describes an automatic drain control and electronic circuit for controlling the quantity of water flowing into a bathtub. However, the quantity of water supplied is dependent on a clock controlled solenoid valve rather than the level of water within the bathtub. Unfortunately, in the event of an increase in water pressure, the quantity of water supplied to the bathtub would exceed the required quantity and may result in an overflow of the bathtub.
U.S. Pat. No. 4,202,060 to Touze discloses a bathtub having a sidewall access and a float controlled water level governing device.
U.S. Pat. No. 4,248,444 to Orszullok discloses a capacitive proximity switch for detecting the level of water within a bathtub.
U.S. Pat. No. 4,080,985 to Eagle, describes the operation of a float which slides within a tube to control the level of water entering a bathtub.
Numerous other devices have been proposed by the prior art for regulating the water level and temperature of washing machines and the like, but none of these devices is readily adaptable to a total liquid dispensing system which is adaptable to a residential, business or medical installation. Although some of the aforementioned patents have solve many of the needs of the prior art by providing liquid level controls and liquid temperature controls, none of the prior art devices teach a device which will selectively control the temperature and flow rate with which the liquid is delivered to a container, maintain the required temperature of liquid within the container and control the level of the liquid within the container in an efficient and economical manner which will permit mass installation of the system in residences, industries, medical complexes, nursing homes and the like.
In our prior U.S. Pat. No. 4,360,935, we disclosed a novel access door in a bathtub for enabling an elderly or an infirm person to readily enter and exit the bathtub without the need of stepping over the peripheral wall of the bathtub.
In another prior U.S. Pat. No. 4,409,694, we set forth a novel system comprising an electronic control and valve system for controlling the function of a bathtub including the temperature and the liquid level within the bathtub. This patent also disclosed many novel independent devices incorporated into the system.
The primary object of the present invention is to improve upon our prior inventions and to provide a system which controls the functions of a bathtub or sink or a complete water dispensing system which is superior in performance and versatility and which is more economical to produce, maintain and operate.
Another object of the present invention is the provision of a system for dispensing liquids having a novel liquid recirculation system which reclaims heated liquids that are under a desired temperature which would normally be discarded thus saving the liquid and the heat energy contained in the liquid.
Another object of the present invention is the provision of a system for dispensing liquids which automatically permits the liquid level to rise to a preselected level within a container and to maintain such level in the event that the volume of liquid is displaced by an object entering the container.
Another object of the present invention is the provision of a liquid dispensing system having an electronic control for regulating the bath and shower functions in a bathtub as well as regulating the water level and the water temperature in the bathtub.
Another object of the present invention is the provision of a liquid dispensing system suitable for use with a bathtub having a side access door which is particularly suitable for use by infirm or aged persons.
Another object of the present invention is the provision of a liquid dispensing system with an electronic control for a bathtub wherein the bathtub incorporates a side access door in which the open or the closed position of the bathtub access door is monitored by the electronic control and interrelated with the other functions of the bathtub.
Another object of the present invention is the provision of a liquid dispensing system having novel valve means for mixing hot liquid and cold liquid to dispense a mixture of the liquids at a preselected temperature.
Another object of the present invention is the provision of a liquid dispensing system wherein the novel valve means diverts liquid from the liquid outlet until the mixed obtains a preselected temperature whereat the liquid may be mixed and/or dispensed from the liquid outlet at a desired temperature.
Another object of the present invention is the provision of a liquid dispensing system wherein the novel valve means is selectable to direct the dispensed liquid to one of a plurality of liquid outputs.
Another object of the present invention is the provision of a liquid dispensing system wherein the novel valve means has a fail-safe operation to prevent accidental burning of a person in the remote event of malfunction of the dispensing system.
Another object of the present invention is the provision of a liquid dispensing system wherein the novel valve means is low cost and is applicable to bathtubs, sinks and the like as well as being applicable to industrial and medical applications.
Another object of the present invention is the provision of a liquid dispensing system wherein the novel valve means may be hydraulically operated from the hydraulic pressure of the liquid input conduit to the valve means resulting in a compact and efficient design and which is electrically isolated from an electronic circuit controlling the dispensing system.
Another object of the present invention is the provision of a liquid dispensing system wherein the electronic control system is programmable to enable independent or simultaneous control of a plurality of liquid outlets with each outlet having specific outlet requirement.
Another object of the present invention is the provision of a liquid dispensing system wherein the electronic control may control the simultaneous functions of multiple liquid outlets where each of the multiple liquid outlets has a different outlet requirement.
Another object of the present invention is the provision of a liquid dispensing system having a programmable electronic control which is capable of controlling the water dispensing requirements of an entire house or an entire building or a complex of buildings.
Another object of the present invention is the provision of a liquid dispensing system incorporating a single valve capable of mixing liquids and distributing the mixed liquids to one of a plurality of liquid outputs.
Another object of the present invention is the provision of a liquid dispensing system incorporating a novel bathtub inlet and water circulation system for maintaining the temperature of the water in the bathtub at a desired temperature.
Another object of the present invention is the provision of a liquid dispensing system having a novel water level sensor means for sensing the level of the water within the bathtub for providing input to the electronic control to maintain a preselected level of water in the bathtub.
Another object of the present invention is the provision of a liquid dispensing system having an electronic control which is programmable to enable the system to be readily adapted to different and varied types of installations and for readily modifying the function of the electronic control upon modification of the installation.
Another object of the present invention is the provision of a liquid dispensing system which may be installed in a conventional bathroom with a minimal amount of alterations with the system being formed of modular components which may be removed and replaced enabling rapid repair of the system in the remote event of a component failure.
Another object of the present invention is the provision of a liquid dispensing system having an electronic control which may be reprogrammed to readily modify the control function to accommodate for future expansion of the number of liquid outlets in the installation.
Another object of the present invention is the provision of a liquid dispensing system suitable for controlling the function of a toilet that flushes with pressurized water enabling a substantial savings of water relative to a conventional toilet.
Another object of the present invention is the provision of a liquid dispensing system which affords a degree of control and flexibility heretofore unknown in the art.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the present invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Although the invention is described with reference to a bathtub, sink and toilet, it should be appreciated by those skilled in the art that the invention may find application in industrial, commercial and medical installations and the like.